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Spring 2009 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />• <br />A photographic comparison to a July 2005 photograph (Figure 11 of the 2005 Subsidence and <br />Geologic Field Observations Report) shows there to be significant filling of the crack by <br />weathering of the overlying colluvium and sandstone outcrop. <br />5.4.2 Location 3 <br />Figure 13 is a photograph of a rockfall located above the drill road to West Flatiron as described <br />in previous annual and semi - annual reports. The fall, which occurred on June 30, 2004, is <br />located above the north edge of the central part of mined Longwall Panel 14. A photograph of <br />the same rockfall area taken during the summer of 2006 is provided in Figure 14 for comparison. <br />The overburden depth to the B -seam at this location is about 1,950 feet. Photographic <br />comparisons of this area since 2004 suggest that no additional subsidence related effects have <br />occurred. However, additional rockfalls due to natural processes may still occur in these rugged <br />cliff areas. As noted in Figure 13, there is evidence that portions of the rock pile located at the <br />base of the cliff face has moved and weathered to some degree and supports additional <br />vegetation. <br />• <br />831 - 032.791 <br />November 2009 <br />Wright Water Engineers, Inc. <br />Page 25 <br />